Updated through online information from Anthony Fountain.
I believe Harvard either sold or donated this instrument to Boston University after acquiring the present Flentrop organ. It was installed in the Concert Hall of the School of Music at 855 Commonwealth Avenue, where it served until destroyed by fire in the early '70s, set, it was noised, by a disgruntled campus radical during a period of unrest.
The late Dr. Max Miller, Music Director of Marsh Chapel at BU in those days, told me he was able to salvage some of the 16' pipes from the instrument and had them added to the Casavant Organ in the chapel. I have no documentation to prove any of this, but do remember Max Miller telling me about it. You might want to contact someone at BU to see if they have any information in their files that confirms what I've written here. I'd love to hear if you have any success. Good luck!
Updated through information adapted from E. M. Skinner/Aeolian-Skinner Opus List, by Sand Lawn and Allen Kinzey (Organ Historical Society, 1997), and included here through the kind permission of Sand Lawn:
On loan from the factory; used by E. Power Biggs on CBS Radio broadcasts; altered in 1950. Sold to E. Power Biggs when replaced by Flentrop in 1957.
"Experimental organ. Entirely unenclosed on 2 1/2 inches of wind pressure. Loaned to Busch-Reisinger Museum (Adolphus Bush Hall), Harvard University. Altered in 1950. Sold to E. Power Biggs. Moved to Boston University; burned in 1971."